Method and Apparatus for Producing Perforated Strings of Separable Packages

ABSTRACT

A vertical form, fill and seal machine includes a pair of reciprocating jaws, located below the product delivery conduit of the machine. The jaws are spaced apart to permit the film tube coming off the product delivery conduit to pass between the jaws after the film tube separates from the product delivery conduit. One of the reciprocating jaws has a toothed blade with a leading edge of the toothed blade extending beyond a leading edge of the one jaw. When the pair of jaws closes, teeth of the blade cut a transversely extending series of perforations adjacent to a transverse seal. Accordingly, the machine outputs a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages is formed.

BACKGROUND OF THE INVENTION

1. Technical Field

Modified vertical form, fill, and seal packaging machines that produce packages held together in a continuous string with tear lines between the packages for subsequent ease of package separation. In particular, the modified machines provide a flexible film package string that has a tear line of perforations between the connected packages of the string for ease of subsequent package separation.

2. Description of The Related Art

Vertical form, fill, and seal packaging machines are commonly used in the snack food industry for forming, filling, and sealing bags of chips and other like products. These machines are used to form packages from packaging-film, fill the packages as they are being formed, seal and separate the package by cutting the packaging-film above the seal. Thus, the machines produce separate filled and sealed packages from package-film.

SUMMARY

The following is a summary of some aspects and exemplary embodiments of the present technology, of which a more detailed explanation is provided under the Detailed Description section, here below.

An exemplary embodiment provides a continuous vertical form, fill and seal machine for making a continuous string of separable connected packages. The machine has several features, including a vertically-oriented product delivery conduit; a film dispensing roller configured to mount thereon a roll of package-forming film; a film tensioner oriented and configured to receive, tension and guide package-forming film dispensed from the dispensing roller; and a package-former located and configured to receive tensioned package-film from the film tensioner and guide the package-film around an outer surface of the product delivery conduit. A heat seal bar adjacent the product delivery conduit seals together longitudinal opposed ends of the package-film around the product delivery conduit to form a film tube as the package-film traverses down the outer surface of the product delivery conduit. The machine includes a pair of reciprocating jaws, located below the product delivery conduit and spaced apart to permit the film tube to pass between the jaws after the film tube separates from the product delivery conduit, one jaw of the reciprocating jaws has a toothed blade, a leading edge of the toothed blade extends beyond a leading edge of the one jaw. When the pair of jaws closes, teeth of the blade cut a transversely extending series of perforations adjacent to a transverse seal. Accordingly, the machine outputs a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages.

Optionally, the reciprocating jaws may be limited to only reciprocal motion.

Optionally, the toothed blade may have a series of teeth spaced equidistant from each other, or a series of pairs of teeth spaced equidistant from each other.

Optionally, each tooth of the blade may comprise wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a peripheral edges of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth. Further optionally, each tooth may have wedges only on a first surface extending laterally along opposite sides of the tooth.

Optionally, the toothed blade may be planar, and each tooth of the blade may be coplanar with the blade and not extending upward or downward out of the plane of the blade. The teeth may each be symmetrical about an axis extending longitudinally through the point of the tooth.

An exemplary method provides a continuous string of separable connected packages from a vertical form, fill and seal machine. The method includes the steps of continuously dispensing packaging-film from a roll of packaging-film, tensioning and guiding the dispensed packaging-film, and enveloping a product delivery conduit with tensioned and guided packaging-film. The method further includes sealing together longitudinal opposed ends of the package- film to form a film tube, moving the film tube down and feeding product into the film tube from the product delivery conduit. The film tube is sealed with a pair of transverse seals, which have a transverse tear line comprising perforations located between them. Continuous operation of the vertical form, fill and seal machine in this manner provides a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages. When required or desired, the string of packages can then be separated into individual packages with ease along the tear lines.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of the present technology will become more readily appreciated by reference to the following Detailed Description, when taken in conjunction with the accompanying simplified drawings of exemplary embodiments. The illustrative, schematic drawings, briefly described here below, are not to scale, are presented for ease of explanation and do not limit the scope of the inventions recited in the accompanying patent claims.

FIG. 1 is a schematic of a vertical form, fill and seal apparatus, in accordance with an exemplary embodiment.

FIG. 2 illustrates a string of connected filled packages produced from a vertical form, fill and seal apparatus in accordance with an exemplary embodiment.

FIG. 3 illustrates an exemplary embodiment of a pair of jaws that include a toothed blade located between a pair of heat sealing elements.

FIG. 4 is a schematic top view of FIG. 3.

FIG. 5 is a perspective view of an exemplary embodiment of a toothed blade.

FIG. 6A is a side view of the exemplary embodiment of FIG. 5.

FIG. 6B is an enlarged view of structure of FIG. 6A, as indicated on the drawing.

FIG. 7 is a view of the other side of the toothed blade of FIG. 5.

FIG. 8 is a perspective view of another exemplary embodiment of a toothed blade.

FIG. 9A is a side view of the exemplary embodiment of FIG. 8.

FIG. 9B is an enlarged view of structure of FIG. 9A, as indicated on the drawing.

FIG. 10 is a view of the other side of the toothed blade of FIG. 8.

DETAILED DESCRIPTION

The following non-limiting detailed descriptions of examples of embodiments of the technology may refer to appended drawing Figures and are not limited to the drawings, which are merely presented for enhancing explanations of features of the technology. In addition, the detailed descriptions may refer to particular terms of art, some of which are defined herein, as appropriate and necessary for clarity.

An exemplary vertical form, fill, seal packaging machine is shown diagrammatically in FIG. 1. This drawing is simplified and does not show the cabinet and support structures that typically surround a machine 100. Packaging-film 110 is unwound from a roll 112 of film and passed through tensioners 114 that keep it taut. Packaging-film is typically polypropylene, polyester, paper, polyolefin extrusions, adhesive laminates, and other such materials, or layered combinations of these film materials. For many food products, where flavor retention is important, a metalized or barrier layer may be used to form the inner-most layer.

The packaging-film 110 passes from the tensioners 114 over a former 116, which directs the packaging-film into a vertical tube around a product delivery conduit 118. As the tube is pulled downward by drive belts 120, the vertical tube of film is sealed along its length by a vertical sealer 122, thereby forming a film tube 133 having a continuous longitudinally extending back seal 132.

The machine applies the pair of heat sealing jaws 126, 128 against the film tube 133 to form a pair of transverse seals 134, 136. One of the pair of transverse seals acts as the top seal of a package created by that cycle, and the other part of the transverse seal acts as the bottom seal of the next package that will be made in the machine. In the prior art, the heat seal jaws also includes a blade that reciprocates in an orbital motion to cut along a line that extends between the pair of seals 134, 136 to release the formed and filled packages 130 sequentially. However, the prior art cannot produce a continuous string 135 of packages 130 that have a transverse tear line 138 between adjacent packages for ease of subsequent separation of the string into individual packages, as illustrated in FIG. 2, for example.

Referring to FIGS. 3 and 4, an exemplary embodiment of heat sealing and perforating jaws shows a pair of jaws 126, 128 that include a toothed blade 150 located between the two heating surfaces 142, 144, of one jaw. The toothed blade 150 may be held fixedly but releasably in position mounted to the jaw. Thus, a shank portion of each tooth projects out from the body of the blade and terminates in a head that forms part of a leading edge of the blade. The leading edge 152 projects beyond the leading end 127 of the jaw such that the teeth 154 of the blade (seen more clearly in FIGS. 5-10) can be urged against a package-film with sufficient force during closing of the jaws to perforate the package-film and thereby form a tear line 138 comprised of spaced perforations caused by, and corresponding to, the spaced apart teeth 154. During jaw closing, the teeth 154 on the leading edge 152 may project into a slot 146 in the opposing jaw after penetrating the packaging-film to avoid inadvertent blunting or other damage to the sharp pointed tips 156 of the teeth 154.

Exemplary non-limiting embodiments of toothed blades 150 are illustrated in FIGS. 5-10. These embodiments may be mounted in a fixed position in a recess in the jaw 128, for example, using the exemplary locating and positioning features 162, 164. Thus, these blades move in unison with jaw 128.

The exemplary embodiment of FIGS. 5-7 has a shank portion projecting out from the body of the blade and terminates in a head portion that includes teeth 154 grouped in pairs, albeit that other multiples in a group may also be used. The exemplary embodiment of FIGS. 8-10 has equidistantly spaced individual teeth 154; each tooth having a shank portion projecting out from the body of the blade and terminating in a sharp head portion. While the illustrated examples have teeth or grouped teeth spaced apart equidistantly, such even spacing, while perhaps aesthetically desirable, is not essential for producing tear lines 138 to separate a continuous string of separable packages.

In the exemplary embodiments, the head portion of teeth 154 have wedges 158 on only one face or surface of the blade 150, while the shank portion is free of such sharpening wedges. The wedges 158 extend along the opposed sides of the teeth, tapering to sharp cutting edges at the peripheral edges of each tooth. The wedges from the opposing sides converge in a sharp pointed tip 156 of each tooth that is able to penetrate packaging-film during normal operation of the vertical form, fill and seal machine. Moreover, the illustrated examples of blades 150 have teeth 154 that are symmetrical about an axis extending through the tip 156.

In the illustrated exemplary embodiments the blades 150 are planar, and the teeth 154 are coplanar with the blades, and do not project out of the plane of the blades 150 either upward or downward.

During an exemplary operation, packaging-film is unwound from a film-dispensing roll 112 of the machine 100. The packing-film is tensioned and guided to a former 116 which guides the packaging-film over a product delivery conduit 118. As the packaging-film, shaped around the product delivery conduit travels along the length of the conduit, opposed ends of the packaging-film are sealed together to form a film tube 133 having a continuous longitudinal back seal 132. Product is delivered to the back-sealed lower region of the tube film 133. The film tube 133 is then sealed with a pair of reciprocating jaws that include a toothed blade 150 located between a pair of heat sealing elements 142, 144. This forms a pair of parallel transverse seals 134, 136 with a tear line 138 comprised of perforations formed by the toothed blade between the seals. Continuous operation produces a string 135 of connected packages 130, as illustrated for example in FIG. 2, that can be later separated along a tear line 138.

From the foregoing, an exemplary method provides a continuous string of separable connected packages from a vertical form, fill and seal machine. The method includes the steps of continuously dispensing packaging-film from a roll of packaging film, tensioning and guiding the dispensed packaging-film, and enveloping a product delivery conduit with tensioned and guided packaging-film. The method further includes sealing together longitudinal opposed ends of the package-film to form a film tube, moving the film tube down and feeding product into the film tube from the product delivery conduit. The film tube is sealed by using opposed reciprocating jaws to create a pair of transverse seals, which have a transverse tear line comprising perforations located between them. Continuous operation of the vertical form, fill and seal machine in this manner provides a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages. When required or desired, the string of packages can then be separated into individual packages with ease along the tear lines.

While examples of embodiments of the technology have been presented and described in text and some examples also by way of illustration, it will be appreciated that various changes and modifications may be made in the described technology without departing from the scope of the inventions, which are set forth in, and only limited by, the scope of the appended patent claims, as properly interpreted and construed. 

1. An continuous vertical form, fill and seal machine for making a continuous string of separable connected packages, the machine comprising: a vertically-oriented product delivery conduit; a film dispensing roller configured to mount thereon a roll of package-forming film; a film tensioner oriented and configured to receive, tension and guide package-forming film dispensed from the dispensing roller; a package-former located and configured to receive tensioned package-film from the film tensioner and guide the package-film around an outer surface of the product delivery conduit; a heat seal bar adjacent the product delivery conduit to seal together longitudinal opposed ends of the package-film to form a film tube as the package-film traverses down the outer surface of the product delivery conduit; and a pair of reciprocating jaws located below the product delivery conduit and spaced apart to permit the film tube to pass between the jaws after the film tube separates from the product delivery conduit, one jaw of the reciprocating jaws having a toothed blade, a leading edge of the toothed blade extending beyond a leading edge of the one jaw; wherein, when the pair of jaws closes, teeth of the blade cut a transversely extending series of perforations adjacent to a transverse seal, whereby a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages is formed.
 2. The machine of claim 1, wherein the toothed blade extends between a pair of sealing surfaces of one of the reciprocating jaws.
 3. The machine of claim 1, wherein the toothed blade comprises a series of teeth spaced equidistant from each other.
 4. The machine of claim 3, wherein each tooth of the blade comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth.
 5. The machine of claim 4, wherein each tooth of the blade has wedges only on one side of the blade.
 6. The machine of claim 1, wherein the toothed blade comprises a series of pairs of teeth, each pair of teeth spaced equidistant from each other.
 7. The machine of claim 6, wherein each tooth of the pair of teeth comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth.
 8. The machine of claim 7, wherein each tooth of the blade has wedges only on one side of the blade.
 9. The machine of claim 2, wherein the toothed blade comprises a series of teeth spaced equidistant from each other.
 10. The machine of claim 9, wherein each tooth of the blade comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth.
 11. The machine of claim 10, wherein each tooth of the blade has wedges only on one side of the blade.
 12. The machine of claim 2, wherein the toothed blade comprises a series of pairs of teeth, each pair of teeth spaced equidistant from each other.
 13. The machine of claim 12, wherein each tooth of the pair of teeth comprises wedges along laterally opposed sides of the tooth, the wedges each terminating in a cutting edge along a perimeter of the tooth, the laterally opposed wedges converging in a sharp point at a leading edge of the tooth.
 14. The machine of claim 13, wherein each tooth of the blade has wedges only on one side of the blade.
 15. The machine of claim 1, wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws.
 16. The machine of claim 2, wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws.
 17. The machine of claim 3, wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws.
 18. The machine of claim 6, wherein motion of the sealing and perforating jaws is restricted to only reciprocating motion, and the blade is fixedly mounted to one of the pair of jaws.
 19. The machine of claim 1, wherein the toothed blade is planar, each tooth of the blade is coplanar with the blade, each tooth has wedges only on a first surface, the wedges each extending laterally along opposite sides of the tooth, each wedge terminating in a cutting edge along a perimeter of the tooth, the wedges converging in a sharp point at a leading edge of the tooth, the tooth symmetrical about an axis extending through the sharp point.
 20. The machine of claim 2, wherein the toothed blade is planar, each tooth of the blade is coplanar with the blade, each tooth has wedges only on a first surface, the wedges each extending laterally along opposite sides of the tooth, each wedge terminating in a cutting edge along a perimeter of the tooth, the wedges converging in a sharp point at a leading edge of the tooth, the tooth symmetrical about an axis extending through the sharp point.
 21. A method of making a continuous string of separable connected packages on a vertical form, fill and seal machine, the method comprising: continuously dispensing packaging-film from a roll of packaging film; tensioning and guiding the dispensed packaging-film; enveloping a product delivery conduit with tensioned and guided packaging-film; sealing together longitudinal opposed ends of the package-film to form a film tube; moving the film tube down and feeding product into the film tube from the product delivery conduit; and sealing and the film tube with a pair of transverse seals having a transverse tear line comprising perforations located between the transverse seals; whereby continuous operation of the vertical form, fill and seal machine provides a continuous string of connected sealed packages having a transversely extending perforation between adjacent packages.
 22. The method of claim 21, wherein the step of sealing comprises reciprocating a pair of jaws comprising a pair of heat sealing elements and a toothed blade to seal the film tube by forming a pair of spaced apart transverse seals and substantially simultaneously creating a perforated tear line between the transverse seals with the teeth of the blade. 